1. Technical Field
The present invention relates to a clutch cover assembly and particularly a clutch cover assembly for pressing a friction member of a clutch disc assembly against a flywheel of an engine and releasing the pressing.
2. Background Art
A clutch cover assembly is generally attached to a flywheel of an engine and used for transmitting the driving force of the engine to a transmission side. The clutch cover assembly is mainly equipped with a clutch cover, a pressure plate, and a diaphragm spring. The clutch cover is fixed to the flywheel. The pressure plate is pressed to the flywheel side by the diaphragm spring and holds a friction member of a clutch disc assembly with and the flywheel. The diaphragm spring has the function of pressing the pressure plate and also has a lever function for releasing the pressing on the pressure plate.
Here, when the wear of the friction member of the clutch disc assembly advances due to the load characteristic of the diaphragm spring, the pressing load on the friction member becomes greater. For this reason, when the friction member wears, a large load becomes necessary to perform the release operation, and the clutch pedal pressure ends up becoming greater.
Thus, as described in patent citation 1 for example, there has been proposed a wear compensating mechanism that is configured to suppress the pressing load from becoming greater by returning the posture of the diaphragm spring to an initial state even in a case where the friction member has worn. The wear compensating mechanism mainly has a fulcrum ring that is placed between the pressure plate and the diaphragm spring, a biasing mechanism that biases the fulcrum ring in a direction away from the pressure plate, and a wear-amount detecting mechanism that detects the wear-amount of the friction member. Here, the diaphragm spring is capable of pressing the pressure plate via the fulcrum ring, and by moving the fulcrum ring to the side away from the pressure plate in accordance with the wear-amount of the friction member, the diaphragm spring is maintained in its initial set posture.
Further, in order to remedy instability in the operation of the wear-amount detecting mechanism caused by vibration, the wear compensating mechanism described in patent citation 2 has also been proposed. Here, a cone spring for absorbing vibration is disposed in the wear-amount detecting mechanism to stabilize the operation for wear compensation.